Ozieri (Sardinian: Otieri) is a comune (municipality) of approximatively 11,000 inhabitants in the Metropolitan City of Sassari, in the Italian region of Sardinia, in the Logudoro historical region.

Its cathedral of the Immacolata is the episcopal see of the Roman Catholic Diocese of Ozieri. Ozieri is the centre of the earliest known archaeological culture on Sardinia (known as Ozieri culture).

Ozieri can be reached from Sassari through the SS.597 National Road and by Olbia (SS.199).

The city has a railway station located in the frazione of Chilivani (lines to Olbia, Porto Torres and Cagliari).